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  1. WiredTiger
  2. WT-3854

Remove write lock from commit path, leaving old entries in queue

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.6.3, 3.7.2, WT3.1.0
    • Component/s: None
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      Description

      In investigating SERVER-31694, I've seen a number of pmp stacks that indicate that the rwlocks protecting the timestamp queues can be a source of contention. Every transaction must take the mutex for writing twice, once when setting a timestamp on a transaction to insert it into the queue and once on commit/rollback to remove the txn from the queue.

      Consider ways to reduce the times a user thread needs to hold that lock. Perhaps on commit/rollback the user thread clears or sets flags and an internal worker thread walks the list and removes transactions from the list so that a commit does not need to acquire that write lock.

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              • Assignee:
                sue.loverso Susan LoVerso
                Reporter:
                sue.loverso Susan LoVerso
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                  Updated:
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